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Subject: Re: Write performance compared to Postgresql
From: Jeff Williams <jeffw@wherethebitsroam.com>
In-Reply-To: <12FE601D-42F7-4C69-9203-238EFA4DBA37@gmail.com>
Date: Tue, 3 Apr 2012 15:18:20 +0200
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Message-Id: <2DA6493E-BE99-4530-9E89-80AE0304C5EB@wherethebitsroam.com>
References: <7B1606F9-19D2-46EB-831D-DF373F3C8E8B@wherethebitsroam.com>
 <12FE601D-42F7-4C69-9203-238EFA4DBA37@gmail.com>
To: user@cassandra.apache.org

Ok, so you think the write speed is limited by the client and protocol, =
rather than the cassandra backend? This sounds reasonable, and fits with =
our use case, as we will have several servers writing. However, a bit =
harder to test!

Jeff

On Apr 3, 2012, at 1:27 PM, Jake Luciani wrote:

> Hi Jeff,
>=20
> Writing serially over one connection will be slower. If you run many =
threads hitting the server at once you will see throughput improve.=20
>=20
> Jake
>=20
>=20
>=20
> On Apr 3, 2012, at 7:08 AM, Jeff Williams <jeffw@wherethebitsroam.com> =
wrote:
>=20
>> Hi,
>>=20
>> I am looking at cassandra for a logging application. We currently log =
to a Postgresql database.
>>=20
>> I set up 2 cassandra servers for testing. I did a benchmark where I =
had 100 hashes representing logs entries, read from a json file. I then =
looped over these to do 10,000 log inserts. I repeated the same writing =
to a postgresql instance on one of the cassandra servers. The script is =
attached. The cassandra writes appear to perform a lot worse. Is this =
expected?
>>=20
>> jeff@transcoder01:~$ ruby cassandra-bm.rb=20
>> cassandra
>> 3.170000   0.480000   3.650000 ( 12.032212)
>> jeff@transcoder01:~$ ruby cassandra-bm.rb=20
>> postgres
>> 2.140000   0.330000   2.470000 (  7.002601)
>>=20
>> Regards,
>> Jeff
>>=20
>> <cassandra-bm.rb>